[texhax] Oblique cancellation with plain TeX

[Rodolfo Medina]

Rodolfo Medina <rodolfo.medina at gmail.com> writes:

> David Carlisle <d.p.carlisle at gmail.com> writes:
>
>> On Fri, 4 Jan 2019 at 22:05, Rodolfo Medina <rodolfo.medina at gmail.com> wrote:
>>>
>>> David Carlisle <d.p.carlisle at gmail.com> writes:
>>>
>>> > \input picture
>>> > \catcode`\@=11
>>> >
>>> > \RequirePackage{cancel}
>>> > \let\zzcancel\cancel
>>> > \def\cancel#1{{%
>>> > \let\line\LaTeX at line
>>> > \zzcancel{#1}}}
>>> >
>>> > $\cancel{x^2 + 1}$
>>> >
>>> > $\cancel{a}$
>>> >
>>> > $\cancel{{x^2 + 1 \over b}}$
>>> >
>>> >
>>> > \bye
>>>
>>>
>>> Fantastic...!!
>>
>> Of course simply using latex gives a better tested codepath than
>> loading a large chunk of latex circa 1993  but you seem to want to
>> avoid doing that for some reason.
>
>
> I've got tons of documents now written in plain TeX and complexly organized
> with macros...  Besides, I imagine LaTeX couldn't do certain things plain TeX
> allows me to do...  Cross references between different files, documents living
> at same time as single articles or/and chapters of book...


...and the result, with \cancel, is absolutely identical between LaTeX and TeX,
using your extract...

Rodolfo